Hands-on: Fitbit's new Flex 2 and Charge 2 Activity Trackers, plus Blaze & Alta updates | DC Rainmaker
Fitbit - Introducing the Cardio Fitness Level feature to #FitbitBlaze ! Coming in Feb, it's like Fitbit Charge 2 and provides a snapshot of your cardiovascular fitness based on your user profile,
Fitbit Charge 2 fitness tracker review - The Gadgeteer